Solid and stable, sometimes centuries old, it is easy to take the walls of your historic building for granted. Yet, walls need to be sensitively maintained and repaired to preserve the stories they tell about regional building traditions or historical changes, like the growing availability of brick in the nineteenth century. Be sure to use matching materials and techniques for any repairs, and avoid the introduction of inappropriate and potentially damaging modern materials, such as cement in place of lime mortar. Traditional finishes like limewash not only look better than modern alternatives; they also allow your building to breathe.